Location: Derinkuyu, Turkiye
Year Discovered: 1960s
Est. Value: Unknown
A Turkish guy who was remodeling his home made one of the most puzzling archeological discoveries when he discovered the entrance to the oldest underground city in the world.
The entrance corridor led to a subterranean metropolis with 18 stories and a depth of up to 250 feet in certain spots.
It is considered as one of the Valuable Discoveries Found In Unexpected Places.